Rubber freezing tray



RUBBER FREEZING TRAY Filed March 28, 1934 Patented sep:` '8, 1936 UNITEDSTATES RUBBER' FREEzrNG TRAY John S. Glomb, Barberton, Ohio, assigner ofone-half to Robert S. Boyle, Akron, Ohio Application March 28, 1934,Serial No. 717,802

. 2 Claims.

` Rubber freezing containers. having individual 10 pockets permit theeasy removal of the ice cubes by flexing the wall of the container, but,because of the low heat conductivity of rubber, containers of thismaterial as heretofore constructed have required more than twice as longas a. metal con- -15 tainer to freeze an equal volume of ice, and thecost of making the -rubberarticle has also been relatively high. Thecontainer of the present invention freezes the ice much more rapidly, it

is less costly to make, permits easier removal of 2g ice cubes and hasmany other advantages which will be pointed out, especially whencombined with a novel metal holder forming a part of the invention.

In prior rubber trays the ice forms first at the 25 top surface of thewater in each pocket, said top surface freezes substantially flat, andbulging of the final solid ice cube occurs at its bottom cr lowerportion; whereas with a metal tray the ice formation is different, beingcharacterized by Of the accompanying drawing, Fig. 1 is a per- I 40lspective view, partly broken away, illustrating a preferred embodimentof my invention including the rubber container and metal holder.

Fig. 2 is a reverse plan view of the assembly. Fig. 3 is a detailsection of a portion of the 45 combined unit, illustrating the mode ofremoval of an ice cube..

Fig. 4 is a vertical section approximately on the Y line 4 4 of Fig. 1.

Inthe drawing, l designates the flexible freez- 50 ing container or trayas a whole, consisting of a continuous thin sheet vof vulcanized rubberformed into a plurality of individual planewalled pockets orcompartments Il, each adapted to hold a body of water for freezing asingle 55 ice block of approximaely cublcal form. The

(ci. ca -1085) pockets are arranged in longitudinal and transverse rowsand of a total number depending upon the sized of the particular tray.They are connected only at their upper edges, by the top web i2 of thesheet, which is extended laterally in nar- 5 row flanges i3 on the fouredges, and the frontedge flange may include a finger tab I4 tofacilitate pulling the container unit out of the freezing compartment inthe refrigerator or lifting the rubber tray out of its holder. 1

Below the top web I2, the lpockets il are isolated from each other byintervening longitudinal and transverse grooves or clefts. The sides ofthe pockets are slightly tapered downwardly as shown, to facilitateremoval of the rubber tray from its metal holder. The walls .of thepockets are preferably of tissue thickness comparable to that of arubber toy balloon; namely of the order of about ten to thirtythousandths, or not more than nl; of an inch, to increase theirfiexibility, decrease the cost of production and facilitate transmissionof heat therethrough, so that the combined thickness of two adjacentpocketwalls need not exceed that of a singlepartition wall in priormolded rubber freezing trays.

This tray may be very economically produced by the dipping process,consisting in the deposit of a film of rubber from a bath of rubberlatex or solution. The latex, for example, is compounded with sulphurfor vulcanizatlon and drying and accelerating ingredients, a form madeof porcelain, wood or other material is given a number of dips todeposit a film of the desired thickness, and the article is thenvulcanized on the form in hot air and thereafter stripped from the form.

My improved holder for the rubber tray comprises a metallic grid l5 ofintermediateand marginal bars i6, i1 placed at right angles and forminga group of rectangular spaces for receiving 40 the individual pockets ilof the tray. The bars are upwardly tapered complementally to the wallsof said pockets so as to fit the latter in close heattransmittingrelation, and are vertically widened as plates of a depth extendingbelow the bottoms of the tray pockets. This holder can be cast in onepiece, of a light, highly conductive metal such as aluminum, or asuitable die-casting alloy. Such a grid increases the freezing speedwith a rubber tray of the form illustrated, even though thetray Wallsmay be thicker than described, its bars exclude the formation of thickfrost on the outer sides of the rubber pockets and, since the grid isrigid and the bottoms of the tray pockets do not rest against the oor ofthe freezing compartment, the combined holder and tray are more easilyreleased when frozen to the floor than are containers of other forms.

Fig. 3 illustrates the manner ofl removal of a frozen ice cube I8 fromone of the pockets Il of the rubber tray. It will be observed that therubber pocket wall can be readily distorted by the operators fingers andits bottom wall pushed up from below as far as necessary to grasp theice cube, and if the ice should stick to the rubber, the pocket can evenbe turned inside out. Each cube can be individually removed in thismanner without bending the tray I as a whole and While said tray isstill in the holder I5, or if it is desired to remove all or a pluralityof the cubes at the same time, the rubber tray can be taken out of itsholder and several cubes pushed upwardly from below at the same time, orthe tray can be inverted or distorted more or less as a whole while theblocks are pushed out.

In the use of my invention, freezing of the ice cubes is accomplished inabout half the time reconductive metal grid I5.

Among further advantages of the invention may bementioned the fact thatfreezing proceeds with substantial uniformity throughout the group oftray pockets, and in each pocket progresses from all sides inwardlyinstead of more rapidly at the top surface of the water as with previousrubber trays. When ice formation begins at the top 1 and progressesdownwardly, it is diillcult to tell when the cube is frozen solid andalso, under such conditions, expansion of the ice in a lateral directionexceeds its vertical expansion so that the rubber partitions and outerwalls of the prior containers will often obtain a permanent set;Whereas, with the present invention, completion of the freezing processis readily observed and expansion is mostly vertical, causing a hump onthe top surface of each frozen cube as shown in Fig. 3. leaving the sideshapes regular and more uniform throughout the group. The use ofrelativelythin rubber walls as previously described further promotes theearly dissipation from the rubber of blooming or volatile constituentsof the compound such as uncombined sulphur and excess accelerator orother ingredients which, while not necessarily harmful, have been found,over an extended period, to impart a taste to the ice cubes from a newrubber tray having walls and partitions of the thickness heretoforeemployed.

It will be understood that the described embodiment of my invention maybe modified in various other forms without departing from the scopethereof as dened in the claims.

I claim:

1. A freezing structure comprising a. highly flexible rubber tray formedwith individual, downwardly-tapering pockets, and a rigid metallicholding grid open at the bottom to permit individual ejection of icecubes from the tray, while in the holder, by upward bending of thebottom walls of said pockets, said grid comprising upwardly-tapering,relatively-deep, plate-like bars fitting the sides of the pockets andextending below their bottoms.

2. A holder for a rubber freezing tray with individual pockets,comprising a rigid, open-bottom, metallic grid formed ofupwardly-tapering, relatively-deep, plate-like bars whose lower edgesconstitute the grid-supporting surfaces.V

' J OHN S. GLOMB.

